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LYMPHOMA IN CATS
Lymphoma (also known as Lymphosarcoma and Non-Hodgkins Disease) is a cancer of the
lymphatic tissue. Lymphatic tissue is a filtration network of vessels and lymph nodes that returns
fluids from the body to the blood stream. Feline lymphoma may be caused by activity of the
Feline Leukemia Virus. Most cats do not have an active (detectable) virus infection at the time of
diagnosis; only cats with active virus are contagious.
DIAGNOSIS
Lymphoma is most commonly found in the digestive tract, lymph nodes, and chest cavity of cats,
although any body system can be affected. Common signs of lymphoma in cats include weight
loss, vomiting and/or diarrhea, painless enlargement of the lymph nodes, and difficulty breathing.
Other cats will have signs of illness from the effects of cancer cells invading normal body tissues.
Samples of affected lymph node, bone marrow, or other tissues must be examined under a
microscope to diagnose lymphoma. During treatment, blood tests help us monitor for side effects
from therapy. Blood tests cannot diagnose lymphoma unless the cancer cells are actually
present in the blood stream (leukemia).
PREVENTION
Vaccination can help prevent feline leukemia virus infection. Vaccination will not help if your cat
already has lymphoma.
TREATMENT
Chemotherapy: Lymphoma is not curable, but therapy can reduce the severity of clinical signs
and add quality time to your cat’s life. Chemotherapy is the most effective form of therapy for
lymphoma. You may be familiar with the side effects of chemotherapy in people. Fortunately,
cats rarely experience the severe side effects seen in people. For instance, cats do not lose hair
from chemotherapy, although their long whiskers may be lost.
Chemotherapy is the use of medications to interrupt the growth of cancer cells. The medications
which are effective in stopping the growth of lymphoma cells will also interrupt the normal
replacement of cells which line the digestive tract and the white blood cells which form in the
bone marrow to help our bodies fight infection. When chemotherapy drugs damage these normal
cells, symptoms can range from a mild, temporary decrease in appetite to loose stools, vomiting,
and fever. Again, most cats have no symptoms; others improve with simple drug store remedies
such as Pepcid AC. Stronger prescription medications including appetite stimulants and
antibiotics are sometimes needed, but less than 1 in 10 patients requires a return visit to the
hospital because of side effects. Our philosophy is that cancer patients should feel better, not
worse, from their therapy.
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LOS ANGELES
(310) 558-6120
ORANGE COUNTY
(949) 552-8274
SAN FERNANDO VALLEY
(818) 888-6882
www.VetCancerGroup.com
SOUTH ORANGE COUNTY
(949) 262-5150
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When cats with lymphoma are treated with chemotherapy, the results are usually dramatic. For
most patients, the lymphoma generally disappears into remission (dormancy) within one or two
weeks of treatment. A microscopic amount of the cancer remains, but the patient has no signs
and enjoys a normal quality of life. Many cats seem to feel better than before the cancer was
diagnosed! Eventually the remaining cancer cells begin to divide and symptoms reappear, but
most cats return into remission with acceleration of their treatment. Unfortunately, the cancer
cells eventually develop resistance, the ability to escape damage from the chemotherapy drugs.
When lymphoma becomes resistant to chemotherapy, or when patients do not receive treatment
for the disease, the cancer overwhelms the rest of the body. Signs include severe lethargy, poor
appetite, difficulty breathing, and eventual death.
Most chemotherapy medications must be given as intravenous (IV) injections. Other medications
are available as tablets and can be given at home. Although many medications can control
lymphoma for short periods of time, chemotherapy is most effective against lymphoma when
combinations of different drugs are used. Different drug combinations, or protocols, are available
and range in cost, effectiveness, frequency of visits and side effects. As oncologists, we will help
you decide which protocol is the best start for your cat. The longest success is generally seen
with a combination of six different medications. Each drug has its individual method of damaging
the cancer cells, which results in the longest period of remission and thus longest life expectancy.
The drugs are used in rotation in order to limit side effects. Induction is the more intense 6 to 7week period when treatments are given weekly and we closely monitor the patient’s response to
therapy. After the disease is under control, maintenance treatments continue to keep the disease
in remission for as long as possible.
PROGNOSIS
With chemotherapy, most cats will reach a complete remission and enjoy happy, healthy lives of
six months or longer- often much longer! The effectiveness of treatment depends on how
advanced the disease is and whether your cat has other health problems. We are still learning
about the factors that result in a wide range of life expectancy. As individuals, each of our
patients will have a slightly different response and outcome. Our goal is to maintain the best
quality of life possible!
LOS ANGELES
(310) 558-6120
ORANGE COUNTY
(949) 552-8274
SAN FERNANDO VALLEY
(818) 888-6882
www.VetCancerGroup.com
SOUTH ORANGE COUNTY
(949) 262-5150